1 /*
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  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
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  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
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 24 
 25 #ifndef SHARE_GC_SHARED_MODREFBARRIERSET_HPP
 26 #define SHARE_GC_SHARED_MODREFBARRIERSET_HPP
 27 
 28 #include "gc/shared/barrierSet.hpp"
 29 #include "memory/memRegion.hpp"
 30 
 31 class Klass;
 32 
 33 class ModRefBarrierSet: public BarrierSet {
 34 protected:
 35   ModRefBarrierSet(BarrierSetAssembler* barrier_set_assembler,
 36                    BarrierSetC1* barrier_set_c1,
 37                    BarrierSetC2* barrier_set_c2,
 38                    const BarrierSet::FakeRtti& fake_rtti)
 39     : BarrierSet(barrier_set_assembler,
 40                  barrier_set_c1,
 41                  barrier_set_c2,
 42                  nullptr /* barrier_set_nmethod */,
 43                  nullptr /* barrier_set_stack_chunk */,
 44                  fake_rtti.add_tag(BarrierSet::ModRef)) { }
 45   ~ModRefBarrierSet() { }
 46 
 47 public:
 48   template <DecoratorSet decorators, typename T>
 49   inline void write_ref_field_pre(T* addr) {}
 50 
 51   template <DecoratorSet decorators, typename T>
 52   inline void write_ref_field_post(T *addr) {}
 53 
 54   // Causes all refs in "mr" to be assumed to be modified (by this JavaThread).
 55   virtual void invalidate(MemRegion mr) = 0;
 56   // Causes all refs in "mr" to be assumed to be modified by the given JavaThread.
 57   virtual void write_region(JavaThread* thread, MemRegion mr) = 0;
 58 
 59   // Operations on arrays, or general regions (e.g., for "clone") may be
 60   // optimized by some barriers.
 61 
 62   // Below length is the # array elements being written
 63   virtual void write_ref_array_pre(oop* dst, size_t length,
 64                                    bool dest_uninitialized = false) {}
 65   virtual void write_ref_array_pre(narrowOop* dst, size_t length,
 66                                    bool dest_uninitialized = false) {}
 67   // Below count is the # array elements being written, starting
 68   // at the address "start", which may not necessarily be HeapWord-aligned
 69   inline void write_ref_array(HeapWord* start, size_t count);
 70 
 71  protected:
 72   virtual void write_ref_array_work(MemRegion mr) = 0;
 73  public:
 74   // The ModRef abstraction introduces pre and post barriers
 75   template <DecoratorSet decorators, typename BarrierSetT>
 76   class AccessBarrier: public BarrierSet::AccessBarrier<decorators, BarrierSetT> {
 77     typedef BarrierSet::AccessBarrier<decorators, BarrierSetT> Raw;
 78 
 79   public:
 80     template <typename T>
 81     static void oop_store_in_heap(T* addr, oop value);
 82     template <typename T>
 83     static oop oop_atomic_cmpxchg_in_heap(T* addr, oop compare_value, oop new_value);
 84     template <typename T>
 85     static oop oop_atomic_xchg_in_heap(T* addr, oop new_value);
 86 
 87     template <typename T>
 88     static void oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
 89                                       arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
 90                                       size_t length);
 91   private:
 92     // Failing checkcast or check null during copy, still needs barrier
 93     template <typename T>
 94     static inline void oop_arraycopy_partial_barrier(BarrierSetT *bs, T* dst_raw, T* p);
 95   public:
 96     static void clone_in_heap(oop src, oop dst, size_t size);
 97 
 98     static void oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
 99       oop_store_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), value);
100     }
101 
102     static oop oop_atomic_xchg_in_heap_at(oop base, ptrdiff_t offset, oop new_value) {
103       return oop_atomic_xchg_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), new_value);
104     }
105 
106     static oop oop_atomic_cmpxchg_in_heap_at(oop base, ptrdiff_t offset, oop compare_value, oop new_value) {
107       return oop_atomic_cmpxchg_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), compare_value, new_value);
108     }
109 
110     static void value_copy_in_heap(void* src, void* dst, InlineKlass* md);
111   };
112 };
113 
114 template<>
115 struct BarrierSet::GetName<ModRefBarrierSet> {
116   static const BarrierSet::Name value = BarrierSet::ModRef;
117 };
118 
119 #endif // SHARE_GC_SHARED_MODREFBARRIERSET_HPP